Blast valve actuator

ABSTRACT

Blast valve assemblies having a rotary or butterfly-type valve member and an actuator including a valve-closing mechanism which is cocked in an inoperative configuration when the valve is open. Pressure on the valve member or a signal to a solenoid incorporated in the actuator unlatches the valve-closing mechanism which slams the valve to its closed position. Reset mechanism is incorporated in the actuator to recock the closure mechanism and reopen the valve.

United States Patent Fritz 5] Feb. 22,1972

[54] BLAST VALVE ACTUATOR 3,420,155 1/1969 Slater ..98/1 19 [72]Inventor: Norman George Fritz, Del Mar Calm 3,459,114 8/1969 Baclim 1..98/1 19 [73] Assignee: lntemational Harvester Company, San PrimaryExaminer-Meyer Perlin Diego, Callf- Attorney-Strauch, Nolan, Neale, Nies& Kurz [22] Filed: Jan. 21, 1969 [57] ABSTRACT [2 1] Appl. No.2 792,263

Blast valve assemblies having a rotary or butterfly-type valve memberand an actuator including a valve-closing mechanism US. Cl which iscocked in an inoperative configuraion when the valve is open. Pressureon the valve member or a signal to a [58] Field of Search 1 37/463,251/73, 98/119 Solenoid incorporated in the actuator matches tm valved,ing mechanism which slams the valve to its closed position. {561References cued Reset mechanism is incorporated in the actuator torecock the UNITED STATES PATENTS closure mechanism and reopen the valve.

3,064,552 11/1962 Ehrsam ..98/l19 21 Claims, 19 Drawing FiguresPAIENTEDFEBZZ I972 3.643.583

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SHEET 130F 13 INVE R NORMAN GEORG RITZ ATTORNEYS BLAST VALVE ACTUATORThe present invention relates to valves and, more specifically. tovalves for protecting turbine intake and exhaust systems. buildinginteriors, etc., from the overpressures caused by nuclear explosions andto novel improved actuators for such valves.

Generally speaking, the novel, improved blast valve assemblies describedherein include a valve member of the butterfly type. a spring-drivenactuator for closing the valve, mechanism for resetting the actuator andopening the valve member, and shock-absorbing mechanism for cushioningthe impact as the valve member reaches its closed position to preventdamage to the components of the valve assembly and to minimize reboundof the valve member.

The major components of the novel actuator incorporated in the valveassembly just described include in addition to the spring which producesthe valve-closing force and the reset mechanism an assembly formaintaining the spring in a compressed configuration, a triggermechanism which is actuatable to displace the assembly just mentionedand release the spring to close the valve member, a latch mechanismwhich is operable to maintain the trigger mechanism in an inoperativeconfiguration, and one or more actuators for freeing the triggermechanism from the restraint exerted by the latch mechanism manually,automatically or upon the occurrence ofa condition dictating the closingof the valve member.

Important and primary objects of the invention are the provision ofnovel, improved actuators for blast valves of the rotary or butterflytype and the provision of blast valve assemblies having novel, improvedactuators for closing the valve member of the assembly.

Other important but more specific objects of the present inventionreside in the provision of novel, improved blast valve actuators which:

I. can be actuated to close a rotary-type blast valve either manually orautomatically.

2. in conjunction with the preceding object, can be automaticallyactuated by the reaction of the valve member to blast wave overpressure.

3. in conjunction with objects Nos. 2 and 3, can be automaticallyactuated by the transmission of an electrical signal to the actuator.

4. are capable of closing a rotary-type blast valve in an extremelyshort period of time.

5. in conjunction with the preceding object. are capable ofaccomplishing the closing of the associated valve automatically onceactuated.

6. in conjunction with the preceding objects 4 and 5, are capable ofclosing the associated valve rapidly without the imposition of damagecausing shock on the valve or actuator components and withoutsignificant rebound of the valve member once it has reached the closedposition.

7. can be reset with concomitant reopening of the associated blast valvefrom a remote location.

8. can be reset manually with concomitant reopening of the associatedvalve.

9. can be actuated to reclose the valve member during the portion of thecycle when the valve is being opened.

l0. cannot be spontaneously or inadvertently actuated.

l I. can be serviced without removal of the valve assembly.

Yet another important object of the present invention is the provisionof novel blast valve assemblies which include valve actuators in accordwith the preceding objects and various combinations thereof.

Other important objects and other novel features and advantages of thepresent invention will become apparent from the appended claims and asthe ensuing detailed description and discussion proceeds in conjunctionwith the accompanying drawing, in which:

FIG. I is a front elevation ofa valve assembly constructed in accordancewith and embodying the principles of the present invention;

FIG. 2 is a side elevation ofthe valve assembly of FIG. 1;

FIG. 3 is a side view of the actuator with its casing in part brokenaway to show its internal components;

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FIG. 4 is a section through the actuator, taken substantially along line44 of FIG. 3;

FIG. 5 is a section through the actuator, taken substantially along line5-5 of FIG. 3;

FIG. 6 is a section through the valve assembly. taken substantiallyalong line 6-6 of FIG. 2;

FIG. 7 is a section through the valve assembly. taken substantiallyalong line 7-7 of FIG. 2;

FIG. 8 is a section through the actuator, taken substantially along 8-8of FIG. 4;

FIG. 9 is a plan view of a roller-lever assembly employed in theactuator;

FIG. 10 is a side view ofthe roller-lever assembly;

FIG. 11 is a transverse section through the roller-lever as sembly andcertain components with which it cooperates;

FIG. 12 is a view of the actuator taken generally along line 12-12 ofFIG. 3 with certain components removed to show other elements of theactuator;

FIG. 13 is a plan view ofa trigger incorporated in the actuator of FIG.3; 7

FIG. 14 is a side view ofthe trigger;

FIG. 15 is a perspective view of the trigger;

FIG. 16 is a view ofthe actuator showing the positions of theroller-lever assembly and other components when the valve is closed andwhen it is being reset;

FIGS. 17 and 18 are partial, enlarged-scale sections through theroller-lever assembly and associated components. showing theroller-lever in and being released from its cocked position; and

FIG. 19 is a view similar to FIG. 8, but with different actuatorcomponents removed.

Referring now to the drawing, FIGS. 1 and 2 depict a blast valveassembly 40 constructed in accord with the principles of the presentinvention. The major components of the valve assembly are a valve member42 rotatably supported in a valve body or duct 44 by trunnions 46, anactuator 48 for moving the valve member from its open to its closedposition, a shock absorber 49 for cushioning the impact on the valveassembly components when valve member 42 reaches the closed position,and a reset mechanism 50 including an electric motor 51 drive-connectedto actuator 48 through a ge'ar-r'eduction-type reset drive 52 forresetting the actuator and restoring the valve member to the openposition after the actuator has been triggered to close the valve. Inthe'event of a power failure or other emergency conditions the actuatormay alternatively be reset and the valve reopened by using crank 53 to.rotate the shaft 54 of motor 50. v

The details of the valve member and body as well as those of motor 50and gear-reduction drive 52 are not part of the present invention.Accordingly, these components will not be particularized further hereinexcept as is necessary to describe the novel features of the invention.

Turning next to FIGS. 3, 4, 8, l2, l6, and 19, on of the most importantcomponents of valve assembly 40 is the novel actuator 48 provided forpivoting valve member 42 from its open position to its closed position.It is critical in the applications in which valves of the type disclosedherein are employed that this closing movement be accomplished asrapidly as possible. Actuator 48 completely fulfills this requirement asit is capable ofclosing valve member 42 in periods having a duration onthe order of as little as 0.05 second.

The major components of actuator 48, housed in a casing 56, include aspring motor 58 which provides the motive force for closing valve member42 and is connected to the latter by a motion transmitting mechanismidentified by reference character 60. With valve member 42 in its normalor open position the springs of spring motor 58 are maintained in thecompressed configuration shown in FIG. 3 by a pivotable roller-leverassembly 62 and a slide assembly 64. Roller-lever assembly 62 isdisplaced to free spring motor 58 and thereby allow it to restore to itsuncompressed configuration and close valve member 42 by a trigger 66pivotably supported from slide assembly 64 and normally maintained inthe inoperative position shown in FIGS. 3, 8, and 19 by a latch 68.

Trigger 66 is actuated to initiate displacement of rollerlever assembly62 by energizing a solenoid 70 to disengage latch 68 from the trigger orby movement of valve member 42 under the influence of an overpressurewhich is transmitted to the trigger through motion transmittingmechanism 60 and a pivotably mounted, double-armed crank 72 which islocated adjacent the trigger. The trigger may also be actuated manuallyby moving latch 68 out ofengagement with it.

Referring now specifically to FIGS. 3 and 16, the valve-closing springmotor 58 includes two concentrically arranged, outer and innercompression springs 74 and 76 of conventional construction housed in acasing 78 which is bolted or otherwise secured to main actuator casing56. Outer spring 74 extends between casing end wall 80 and a fitting 84fixed to one end of a shaft 86 which is the input member of motiontransmitting mechanism 60. Inner spring 76 is similarly disposed betweenfitting 84 and end wall 80. Shims adjacent support 88 can be removed orincreased in number to vary the force which spring motor 58 is capableof exerting when it is released.

At the upper end of motor 58 as shown in FIG. 3, springs 74 and 76 aremaintainedin the proper position relative to each other and to casingmember 82 by shims 90 and by a cylindrical guide 92 bolted to end plate80. A similar function is performed at the opposite end of the motor bya cylindrical guide 94 fixed to fitting 84.

Referring next to FIGS. 4, 8, and 16, shaft 86 extends through slideassembly 64, which is slidable on the shaft and is butted against theshaft-carried fitting 84 when springs 74 and 76 are compressed. Slideassembly 64 is accordingly driven downwardly as shown in FIG. 16 whenroller-lever assembly 62 is displaced to the position shown in dottedlines in this Figure by actuation of trigger 66, freeing the springs forrestoration to their uncompressed configuration to close valve member42. Slide assembly 64 thus forms the second link in motion transmittingmechanism 60. In addition slide assembly 64 carries trigger 66 and thesolenoid 70 and crank 72 which can be actuated to free the trigger fromthe restraint exerted by latch 68.

Referring now specifically to FIGS. 4, 8, and 16, slide assembly 64 hasa longitudinal bore 98 through which shaft 86 extends. the relativedimensions of this bore and the shaft being such that the slide assemblyis freely slidable on the shaft. Slide assembly 64 is restrained againstrotation or twisting on shaft 86 by a longitudinal projection 100 whichslides in a longitudinally extending groove or way 102 formed in wallmember 104 of actuator casing or housing 56.

The next link in the motion-transmitting linkage 60 connecting springmotor 58 to valve member 42 is provided by a pair ofelongated members orlinks 106, which may be formed from conventional bar stock. At one end,links 106 are fixed to slide assembly 64 by pin 108, which extendsthrough aligned openings 110 in slide assembly legs 112 and apertures114 in link members 106. A sleeve bearing 115 surrounding pin 108 andextending through openings 110 and 114 and abutting slide assembly legs112 provides freedom of rotation for link members 106. Pin 108 issecured in place by washer 116 and nut 118.

At their opposite ends link members 106 extend through slots 120 intransversely spaced, laterally extending arms 122 of a crank 124 (seeFIGS. 3-5, 8, and 16), which is the next link of the motion-transmittingmechanism 60 connecting motor 58 to valve member 42. Link members 106are pivotally fixed to crank arms 122 by pivot pins 126 which areretained in place by washers 128 and cotter keys 130.

As best shown in FIGS. 2 and 5, crank 124 is fixed to a transverselyextending shaft 132 rotatably journaled in.

openings 134 and 136 in actuator housing sidewalls 138 and 140 withwashers 142 and 144 interposed between the crank and the housingsidewalls to insure freedom of rotation (both of the two washers 144 maybe placed on the same side of the crank to align the slots 120 in crankarms 122 with link members 106, if necessary).

At the right-hand end of shaft 132 as shown in FIG. 5, a gasket 146 andcover 148 are attached to casing sidewall 138 in any convenient fashionto keep dust from penetrating to the interior of the casing throughopening 134.

The left-hand end of shaft 132 extends through the opening 136 insidewall 140 and is rotatably connected to one of the two valve membersupporting trunnions 46 by shaft 152. More specifically, the ends ofshaft 152 are externally splined and extend into internally splinedsockets 154 and 156 in shaft 132 and trunnion 46, rcspectively, therebyfixing the trunnion and blade member to shaft 132 for rotationtherewith.

To elaborate on the closing movement of valve member 42 by the mechanismjust described, the displacement of rollerlever assembly 62 by trigger66 removes the restraint on compressed springs 74 and 76 whichaccordingly expand, driving fitting 84, shaft 86, slide assembly 64, andlink members 106 downwardly as shown in FIGS. 3, 8, and 16. This rotatescrank 124, crankshaft 132, and splined shaft 152 clockwise as shown inFIGS. 3 and 16, thereby pivoting valve member 42 from the open positionidentified by reference character 158 in FIG. 16 to the closed positionidentified by reference character 160 (see FIG. 3). As indicated above,this all takes place in an extremely short period of time, which istypically not in excess of 0.05 second.

Because of the rapidity with which it is moved by spring motor 58, valvemember 42 is capable of reaching its closed position with sufficientforce to damage the valve member as well as the members ofmotion-transmitting mechanism 60 and other components of actuator 48. Toabsorb this shock and thereby prevent damage to the components justmentioned, the shock absorber 49 mentioned above is employed. Shockabsorber 49, which may be of conventional hydraulic construction,includes a cylinder 164 bolted to casing wall member 104 and a piston orplunger 168 disposed in the path of valve member 42 as shown, in FIGS. 3and 16. The operation of shock absorber 49 is conventional, its plunger168 being driven into cylinder 164 to cushion the shock as the plungeris struck by the valve member.

To keep valve member from fluttering after it reaches the closedposition, the hold closed mechanism 170 shown in FIGS. 2 and 6 isprovided. This mechanism includes an elongated arm 172 bolted to aflange 174 on an intermediate cas ing 177 and a tension spring 178. Asbest shown in FIG. 6, one end of spring 178 is fixed to member 172adjacent its outer or free end by a nut-and-bolt arrangement 180, 181and a spacer 182. The opposite end of spring 178 is connected via a link184 to a plate 186 bolted to the outer end of the valve membersupporting trunnion 46 nearer actuator 48.

As mentioned above, valve member 42 rotates in a clockwise direction asshown in FIGS. 1, 3, 6, and 16 in moving from the open position to theclosed position. As will be apparent from FIG. 6, spring 178 exerts aclockwise force on valve member 42 through plate 186, which is removedfrom the axis of valve member rotation, and trunnion 46. In other words,spring 178 exerts a force in the closing direction to bias the valvemember toward the closed position and prevent it from fluttering.

As best shown in FIG. 6, there are a series of apertures 188 in assemblymember 172 through which bolt may be inserted. By inserting the bolt indifferent ones of these apertures, the tension on spring 178 and,accordingly, the force which the spring exerts on valve member 42 can beadjusted.

Referring still to FIG. 6, a pointer 190 is formed on the outer, freeend of valve plate 186. This pointer cooperates with a positionindicating plate 192 bolted to the side of flange 174 opposite member172 to provide a visual indication of the position of valve member 42.

Turning now to FIGS. 2 and 7, an indication of the position of valvemember 42 is also provided at a remote location by an arrangementincluding two microswitches 194 and 196 disposed within and bolted tothe intermediate casing 177 between valve casing 44 and actuator casing56. As shown in FIG. 7, microswitches 194 and 196 have plunger-typeactuators 200 engageable by a lobe 202 on the splined shaft 152drive-connecting crank shaft 132 of actuator 48 andvalvemember-supporting trunnion 46. With valve member 42 in the openposition, lobe 202 depresses the actuator and closes the contacts ofmicroswitch 196. Similarly, with valve member 42 in the closed position,lobe 202 depresses the actuator and closes the contacts of microswitch194. The contacts of the two microswitches are connected through leadsidentified generally by reference character 204 to a power source (notshown) and to indicator lamps (likewise not shown) which may be disposedat any desired location or locations. The appropriate lamp is lit by theclosing of the associated microswitch when the valve member isrespectively in the open position and the closed position.

Referring now to FIGS. 3, 812, and 16-18, the roller-lever assemblyemployed to retain springs 74 and 76 in the compressed configurationshown in FIG. 3 includes a main casing or lever 206 pivotally fixed tovertically oriented bracket 208 by a pivot pin 210, which extendsthrough arms 212 of the lever and bracket 208 and is secured in place bya nut 214 (see FIG. 12). Bracket 208 is in turn fixed to shaft'86 ofmotiontransmitting mechanism 60 by a bolt 216 and is maintainednonrotatable in actuator casing 56 by a horizontally projecting lug 218disposed in an elongated guide or way 220 in actuator casing wall 222.Guide "220 is parallel to shaft 86 and thereby permits bracket 208 androller-lever assembly 62 to move downwardly as shown in FIG. 16 withshaft 86 as valve member 42 is pivoted from its open to its closedposition.

Lever 206 is normally maintained in the operative or springrestrainingposition by a spring 224 seated at one end in a spring seat 226 inbracket 208and seated at the opposite end in a seat 228 in lever 206.

Referring now specifically to FIGS. 8-12, in the configuration shown inFIG. 3, roller-lever assembly 62 maintains the springs 74 and 76 ofspring motor 58 in the compressed configuration by preventing downwardmovement of slide assembly 64 as shown in this Figure. Morespecifically, a pair of lateral, transversely extending,, spaced-apartprojections 230 are formed on the slide assembly 64. Abuttingprojections 230 on the lower side thereofis a transversely extendingroller 232 secured to slide assembly 64 as by capscrews 234. Engagingroller 232 when lever 206 is in the position shown in FIGS. 3 and 8 arethree rollers 236, 238, and 240 of the same diameter as roller 232,These three rollers also extend at right angles to shaft 86 and are soaligned with roller 232 that the longitudinal axes of all four rollerslie in a common plane 241 which is parallel to a plane including thelongitudinal axis ofshaft 86.

Turning now to FIGS. 9-11, rollers 236, 238, and 240 are carried bylever 206 and, more specifically, have reduced diameter end portions 242which extend into vertical recesses 244 in cage plates 246 bolted to thefree or left-hand end of lever 206. The lower ends of recesses 244 areclosed so that rollers 236 and 238 may move with respect to lever 206but are retained in the lever along with roller 240 as the lever isdisplaced from the position shown in FIGS. 3 and 8.

As best shown in FIG. 8, an insert 247 is interposed between roller 240and lever 206 and held in place by one or more pins 248. This inserttransmits the thrust from roller 240 to lever 206 and, in addition,keeps rollers 236, 238, and 240 in engagement with each other and withthe roller 232 carried by slide assembly 64.

Referring now to FIGS. 17 and 1 8, the force exerted by compressedsprings 74 and 76 is transmitted through fitting 84 and slide assembly64 to the roller 232 carried by the latter. With rollers 236, 238, and240 aligned with roller 232; i.e., with their longitudinal axes lying inplane 241, the force exerted by the springs is transferred from roller232 through the rollers 236, 238, and 240, lever 206, and bracket 208 toshaft 86. Shaft 86 is normally prevented from moving longitudinally byreset mechanism 50 as will become apparent hereinafter. Accordingly, aslong as movable rollers 236, 238, and 240 remain aligned, springs 74 and76 are prevented from expanding; and valve member 42 remains in the openposition.

Referring now particularly to FIGS. 8, 10, 17, and 18, the roller 240 ismaintained in its aligned position by a depending projection 248a onlever 206, and movable rollers 236 and' tially seated in a recess 262 inlever arm 206 and provided with a projection 264 extending through anaperture 266 and provided plate 250. Interposed between rocker pin 260and movable rollers 236 and 238 and equidistantly spaced on oppositesides of the center of the pin are push rods 267 which extend throughapertures 268 in the lever arm. Accordingly, spring 256, acting throughrocker plate 250, rocker pin 260, and push rods 267 exerts a biasingforce on rollers 236 and 238, holding them against the free surface 270of slide assembly 64, which is finished to very close tolerances so thatthe alignment of rollers 232,236,238, and 240 will be very accurate.

Referring now to FIGS. 8, l7, and 18, roller-lever assembly 62 isdisplaced to free the springs 74 and 76 of spring motor 58 forvalve-closing operation by moving roller 236 to the right against theforce exerted by spring 256 and simultaneously moving roller 238 in theopposite direction. When this is done, the restraint exerted upon theslide assembly through roller 232 is removed, and spring motor 58,acting through fitting 84, forces slide assembly 64 downwardly as shownin FIGS. 3, 8, and 16. As it moves downwardly, the slide assembly pivotsthe roller-lever assembly to the right about pivot pin 210 to theposition shown in dotted lines in FIG. 16; and valve member 42 closes asdescribed above.

The movement of roller 236 just described is effected by actuation ofthe trigger 66 mentioned briefly above. More specifically, referring nowparticularly to FIGS. 3, 12-15, and 17-19, trigger 66 includes atransversely extending web 272 from which three parallel, spaced-apartlegs 274, 276, and 278 extend. Trigger 66 is pivotably fixed to slideassembly 64 by a pivot pin 280 which extends through transverselyaligned apertures 282 in trigger legs 274 and 278 and the twoprojections 230 of slide assembly 64 against which roller 232 is butted.

Pivot pin 280 is retained in place in any convenient fashion such as bythe nut 284 and cotter key 286 shown in FIG. 12. Trigger 66 is'biased tothe normal inoperative position shown in FIG. 19, for example, by aspring 288. As best shown in FIGS. 11 and 19, spring 288 is disposedbetween a spring seat 290 at the free end of trigger leg 278 and aspring retainer block 292 bolted to slide assembly 64. Spring 288accordingly biases the forward portion of trigger 66 about pivot pin280, thereby maintaining the trigger in the inoperative, normalposition.

Trigger 66 is actuated for displacement of roller 236 by per mitting itto pivot about pivot pin 280 in a counterclockwise direction as shown inFIG. 19 under the influence of spring 288. As best shown in FIGS. 3 and19, the trigger is normally restrained against this movement by latchassembly 68, which includes a horizontally extending arm 294 and acircularly sectioned detent 296 fixed to the right-hand end of the armin any convenient fashion. Latch assembly arm 294 is pivotally fixed toa bracket 298 bolted to the lower end of solenoid mounting bracket 300by a pivot pin 301. The arm is separated from bracket 298 by shims 302,which permit arm 294 to be adjusted so that detent 296 will seat in acorrespondingly configured recess 304 in the forward end of trigger arm274.

Trigger 66 can be freed for counterclockwise rotation to itsroller-displacing position by pivoting latch assembly member 294 in aclockwise direction about pivot pin 301 as shown in FIG. 19, therebydisplacing detent 296 from restraining engagement with trigger arm 274.This is accomplished by energizing solenoid 70 which has an actuator 306fixed to the lefthand end of latch assembly member 294 and is supportedfrom slide assembly 64 by the mounting bracket 300 just mentioned.Specifically, the solenoid is attached to bracket 300 as by a nut 308,which clamps the threaded rear end portion of the solenoid against alateral extension 310 of the bracket.

Solenoid 70 is energized by completing a circuit through its coil (notshown) in any appropriate fashion. This may be done, for example, byclosing a switch manually or by employing a pressure or other parameterresponsive switch. Upon energization, the actuator 306 of the solenoidis retracted (i.e., moves upwardly as shown in FIG. 19). This pivotsmember- 294 in a clockwise direction as shown in the samefigure,'freeing detent 296 from trigger arm 274. Thereupon the triggerpivots in a counterclockwise direction under the influence ofspring 288.

Referring now specifically to FIGS. 17 and 18, center trigger leg 276has an upwardly directed extension 312 disposed in a longitudinal groove314 in shaft 86 with the trigger leg aligned with movable roller 236 ofroller-lever assembly 62 and engageable with the roller through anopening 316 in slide assembly 64. Accordingly, as trigger 66 pivotscounterclockwise, middle leg extension 312 moves to the right,displacing roller 236 from the position shown in FIG. 17. As roller 236moves to the right, it displaces the associated push rod 267 in the samedirection, pivoting rocker pin 260 in a clockwise direction relative torocker plate 250 as shown in FIG. 18. This in turn causes the rocker pinto push the rod 267 associated with roller 238 to the left displacingroller 238 in the opposite direction from roller 236. The net result isa displacement of roller 236 to the right out of plane of alignment 241and a corresponding leftward displacement of roller 238. As discussedabove, this removes the restraint exerted by the rollers on slideassembly 64 and thereby frees the springs 74 and 76 of motor 58 forvalve closing operation.

As indicated previously, the actuation of trigger 66 to initiate thevalve-closing operation through displacement of roller 236 in the mannerjust described is also automatically accomplished by the arrival of ashock wave of sufficient intensity to produce an overpressure of, apredetermined minimum magnitude on valve member 42. Specifically, if theoverpressure exerted on valve member 42 is high enough. it will displacethe valve member past the closed position in which it is normallyretained by the interaction between shock absorber 49 and actuator crack124, causing trunnions 46, splined shaft 152, crankshaft 132, and crank124 to rotate in a clockwise direction as shown in FIGS. 3 and 16,moving link members 106 downwardly as shown in the same Figures.Referring now specifically to FIGS. 12v and 19, link members 106 arefixed to lateral arms 320 of the lever or toggle 72 mentioned above bythe same pin 108 operatively connecting the link members to slideassembly 64. As shown in the same figures, toggle 72 is pivotallysupported from the slide assembly by the same pivot member 280 astrigger 66. Accordingly, the movement oflink members 106 pivots toggle72 in a counterclockwise direction as shown in FIG. 19. As the togglemoves in'the counterclockwise direction, the lower end ofits arm 324moves to the right, and a trip plate 326 bolted to arm 324 engagestrigger arm 274 with sufficient force to move it out of engagement withdetent 296. This frees the trigger for counterclockwise movement underthe influence of spring 288. From this point the valve-closing operationof actuator 48 is as described above.

In conjunction with the foregoing, toggle 72 is normally maintained inan inoperative position with trip plate 326 separated from trigger arm274 by a spring 328. This spring is disposed in a longitudinallyextending aperture 330 in slide assembly 64 around a plunger 332 and issecured in place by a spring cap 334 fixed to the slide assembly in anyconvenient fashion (see FIGS. 3 and 8). Spring 328 biases pivot pin 108upwardly as shown in FIG. 8, thereby biasing toggle 72 in a clockwisedirection about pivot pin 280 to maintain trip plate 326 out ofengagement with trigger 66. In the normal position the distance betweenthe components just mentioned can be adjusted by varying the number ofshims 335 between the trip plate and toggle arm 320.

As best shown in FIG. 8, the openings in slide assembly 64 through whichpivot pin 108 extends are considerably larger in diameter that the pivotpin. This permits movement of the pivot pin relative to the slideassembly under the over pressure conditions described above to actuatetrigger 66. This is necessary since, if the pivot pin and openings 110were the same size, it would be impossible to pivot toggle 72 aboutpivot pin 280. Specifically, this would require movement of slideassembly 64 downwardly as shown in FIG. 8; and this is of courseprevented by the restraining influence of roller-lever assembly 62. v

As mentioned above, trigger 66 may also be actuated I manually toinitiatevalve-closing operation of actuator 48. This is accomplished byemploying a suitable tool to displace trigger arm 274 out of engagementwith detent 296 to free it for movement in'a counterclockwise directionby spring 288.

Provision is also made in valve assembly 40 for resetting actuator 48and restoring valve member 42 to the open position after the valvemechanism had been closed. As mentioned above, this is accomplished by areset mechanism 50 which includes an electric motor 51 having an outputshaft 54 connected to a gear reduction drive 52 of conventionalconstruction.

Referring now specifically to FIGS. 1 and 16, the output shafts 336 ofthe gear reduction drive is rotatably supported from reset mechanismhousing 338 as by a bearing 340 and journals a pinion 342 which is fixedto shaft 336 for rotation therewith..Pinion 342 meshes with a gear 344journaled on and rotatable about a threaded shaft 346 extendinglongitudinally through reset mechanism housing 338 in alignment with theshaft 86 of motion-transmitting mechanism 60. Threaded shaft 346 isfixed to shaft 86 by a square head 348 on the threaded shaft fitted intoa correspondingly configured recess 350 in shaft 86 and a pin 352 whichretains head 348 in recess 350. This arrangement fixes threaded shaft346 against rotation since shaft 86 is prevented from rotating by thecooperation between the lug 218 on roller-lever assembly mountingbracket 208 and the elongated guide 220 in actuator housing wall member222. I 7 Referring again to FIG. 1, gear 344 has an internally threadedhub portion 354 through which shaft 346 is threaded. Accordingly, asgear 344 is rotated, threaded shaft 346 is moved axially along a linecoincidental with the longitudinal axis of shaft 86. v

To reset actuator mechanism 48 and reopen valve member 42, motor 51 isenergized to rotate gear 344 through gearreduction drive 52 and pinion342 in a direction effective to move threaded shaft 346 downwardly asshown in FIG. 1. As shaft 346 moves down, it pulls shaft 86 with itdueto the connection between the two shafts. Roller-lever assembly 62also moves downwardly since the bracket 208 on which it is mounted isbolted to shaft 86.

Referring now to FIG. 3, as roller-lever assembly 62 moves downwardly,the lever is engaged by a roller 356 rotatably supported from actuatorcasing wall member 222 by axle 358 and bracket 360. As the downwardmovement continues, roller 356 pivots roller-lever assembly 62 in acounterclockwise direction as shown in FIG. 16 about pivot member 210until roller 240 is again seated on the surface 270 of slide assembly64.

At the same time that roller-lever assembly 62 is being pivoted byroller 356, the roller-lever assembly pivots trigger 66 in a clockwisedirection about pivot member 280 due to the engagement between roller356 and the projection 312 on trigger finger 276. Accordingly, as theroller-lever assembly reaches its normal, spring motor restrainingposition as best shown in FIG. 19, and is engaged and retained there bythe reseating of detent 296 in the recess 304 at the end of triggerfinger 274.

Following reset of the roller-lever assembly, trigger, and latch, thesaddle or bracket 208 from which the roller-lever assembly is supportedengages and depresses the actuator 362 of a switch 364 supported fromactuator housing wall member 222 (see FIG. 3). Through a conventionalcircuit (not shown) this reverses the flow of current through the motorwindings, causing its output shaft 54 to rotate in the oppositedirection. This causes shafts 346 and 86 to move upwardly as shown inFIGS. 3 and 16. As shaft 86 is pushed upward, it moves rollerleverassembly 62 in the same direction. Since the latter has at this pointbeen reset, it in turn forces slide assembly 64 in the same direction.Due to the abutted relationship of the slide assembly and fitting 84,this displaces the lower ends of springs 74 and 76 upwardly,recompressing them.

Referring now to FlGS. 3 and 16, as the springs 74 and 76 of springmotor 58 reach their fully compressed configurations, a projection 366on roller-lever mounting saddle 208 (see FIGS. 8 and 16) engages anddepresses the actuator 368 of a second microswitch 370 (see F l6. 19)supported from actuator casing wall member 222. This opens the contactsof switch 370, interrupting the flow of current to motor 51 andcompleting the resetting cycle. Because of the longitudinal thrustexerted by the springs 74 and 76 of spring motor 58, there isconsiderable friction between the cooperating external threads on shaft346 and internal threads in hub 354 when motor 51 is deenergized. Thisfriction prevents gear 344 from rotating and permitting shaft 86 to movein the valve-member-closing direction (ie. downwardly as shown in FIGS.3 and 16, for example).

Asmentioned above, the reset cycle just described may also beaccomplished manually in the event of a power failure or the like. Thisis accomplished simply by employing the crank 53 to rotate the outputshaft of motor 54.

One of the important advantages of the novel resetting cycle justdescribed is that the valve can be reclosed during the reset cycle, ifnecessary. Specifically, it will be apparent from the foregoingdescription of this cycle that the roller-lever assembly 62 and slideassembly 64 are in the same relative positions while springs 74 and 76are being compressed as they are whenthe valve is open and thesecomponents are in he positions shown in FIG. 16. Accordingly, should theminimum required overpressure be exerted on the valve member or trigger.66 be actuated manually or by solenoid 70 after the latch has been resetand the upward movement of shaft 86 started, the valve member can bereclosed in the manner described above.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered .in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent 1. Anactuator for a valve having a valve member movable between open andclosed positions comprising resilient biasing means; a motiontransmitting linkage having a rectilinearly movable input memberoperatively connected to said resilient biasing means and an outputmember adapted to be operatively connected to the valve member;retaining means for retaining said resilient biasing means in acompressed configuration, said last-mentioned means comprising apivotally mounted lever, a plurality of relatively movable elementscarried by said lever, one of said elements being engageable withabutment means on the input member of the motion-transmitting linkage,and means for normally maintaining said relatively movable elementsaligned along an axis parallel to the direction of movement of saidinput member to restrain said member and the resilient biasing meansagainst movement; and means for moving at least one of said movableelements out of alignment with the remainder of said elements to 10remove the restraint upon the input member and resilient biasing means.

2. The actuator of claim 1, wherein said retaining means furtherincludes means biasing said lever about its pivot axis toward a positionin which the relatively movable elements are aligned along the axisparallel to the direction of movement of the input member of themotion-transmitting linkage.

3. The actuator of claim 1, together with means operable by the movementof one of said relatively movable elements in one direction generally atright angles to the direction of movement of the input member of themotion-transmitting mechanism out of its aligned position to displaceanother of said elements out of its aligned position in the oppositedirection.

4. The combination of a pivotally mounted valve member movable betweenopen and closed positions and an actuator for said valve member, saidactuator comprising resilient biasing means; means for retaining saidresilient biasing means in a compressed configuration; amotion-transmitting linkage operatively connected between said resilientbiasing means and said valve member which includes a member fixed forrotation with said valve member for displacing said retaining means topermit said resilient biasing means to restore to its uncompressedconfiguration and concomitantly actuate said motion-transmitting linkageso as to move the valve member from its open position to its closedposition; shock-absorbing means engageable by said fixed member as valvemember approaches its closed position to cushion the impact on thecomponents of the valve actuator as the valve member reaches said closedposition; and means for thereafter recompressing said resilient biasingmeans and resetting said retaining means to the configuration in whichit maintains said biasing means in said compressed configuration.

5. The combination of claim 4, together with means for indicating theposition of the movable valve member.

6. The combination of a valve member movable between open and closedpositions and an actuator for said valve member said actuator comprisingresilient biasing means; means for retaining said resilient biasingmeans in a compressed configuration; a motion-transmitting linkageoperatively connected between said resilient biasing means and saidvalve member which comprises first and second relatively movablemembers, one of said members being engageable with said resilientbiasing means and the means for retaining the resilient biasing means inthe compressed configuration being connected to the second of saidmembers for movement therewith; means for displacing said retainingmeans to permit said resilient biasing means to restore to itsuncompressed configuration and concomitantly actuate saidmotion-transmitting linkage so as to move the valve member from its openposition to its closed position; and means for thereafter recompressingsaid resilient biasing means and resetting said retaining means to theconfiguration in which it maintains said biasing means in saidcompressed configuration, said lastmentioned means including means formoving the second member relative to the first member in a firstdirection; means for restoring said retaining means to the position inwhich it is capable of maintaining the resilient biasing means in acompressed configuration as said second member moves in said firstdirection; and means for thereafter moving said first and second membersin a second direction to recompress said resilient biasing means.

7. The combination of a valve member movable between open and closedpositions and an actuator for said valve member, said actuatorcomprising resilient biasing means; means for retaining said resilientbiasing means in a compressed configuration; a motion-transmittinglinkage operatively connected between said resilient biasing means andsaid valve member, the motion-transmitting linkage comprising first andsecond relatively movable members, one of said members being engageablewith said resilient biasing means, the second relatively movable memberof the motion-transmitting linkage being threaded into a fixed actuatorcom- Anund Into means to restore to its uncompressed 'configurationandconcomitantly actuate said motion-transmitting linkage so as to move thevalve member from its open position to its closed position; and meansfor thereafter recompressing said resilient biasing means and resettingsaid retaining means to the configuration in which it maintains saidbiasing means in said compressed configuration, the means for resettingsaid retaining meansand recompressing said resilient biasing meanscomprising means for moving thesecond member relative to the firstmember in a first direction; means for restoring said retaining means tothe position in which it is capable of maintaining the resilient biasingmeans in a compressed configuration as said second member moves in saidfirst direction; and means for thereafter moving said first and secondmembers in a second direction to recompress said resilient biasingmeans, the means for moving said first member comprising drive means forrotating said member.

8. The combination of claim 7, wherein said drive means comprises amotor drive connected to said first member.

9. The combination of claim 7, wherein said drive means comprises meansfor rotating said first member manually.

10. The combination of a valve member movable between open and closedpositions and an actuator for said valve member, said actuatorcomprising resilient biasing means; means for retaining said resilientbiasing means in a compressed configuration; a motion-transmittinglinkage operatively connected between said resilient biasing means andsaid valve member which comprises a rectilinearly movable input clementengageable by said resilient biasing means, an output member fixedrelative to said valve member for rotation therewith, and anintermediate link pivotally fixed at one end relative to said inputmember and pivotally fixed at the opposite end to said output member;means for displacing said retaining means to permit said resilientbiasing means to restore to its uncompressed configuration andconcomitantly actuate said motion-transmitting linkage so as to move thevalve member from its open position to its closed position; and

means for thereafter recompressing said resilient biasing means andresetting said retaining means to the configuration in which itmaintains said biasing means in said compressed configuration. 7

II. The combination of a valve member movable between open and closedpositions and an actuator for said valve member, saidactuator-comprising resilient biasing means; means for retaining saidresilient biasing means in a compressed configuration; a motiontransmitting linkage operatively connected between said resilientbiasing means and said valve member which comprises first and secondrelatively movable'members, one of said members being engageable withsaid resilient biasing means and the means for retaining the resilientbiasing means in the compressed configuration being connected to thesecond of said members for movement therewith; means for displacing saidretaining means to permit said resilient biasing means to restore to itsuncompressed configuration and concomitantly actuate saidmotion-transmitting linkage-so as to move the valve member from its openposition to its closed position; and means for thereafter recompressingsaid resilient biasing means and resetting said retaining means to theconfiguration in which it maintains said biasing means in saidcompressed configuration which comprises means for moving the secondmember relative to the first member in a first direction, means forrestoring said retaining means to the position in which it is capable ofmaintaining the resilient biasing means in a compressed configuration assaid second member moves in said first direction, and means forthereafter moving said first and second members in a second direction torecompress said resilient biasing means said last-mentioned meansincluding an electric motor, a first switch means for reversing thedirection of rotation of said motor when said first member has moved inthe first direction a distance sufficient to effect reset of saidretaining means and second switch means for deenergizing said motor whensaid first and second members have moved a distance sufficient torecompress the resilient biasing means to its compressed configuration.

12. The combination of a valve member movablebetween open and closedpositions and an actuator for said valve member, said actuatorcomprising resilient biasing means; pivotally mounted means forretaining said resilient biasing means in a compressed configuration; amotion-transmitting linkage operatively connected between said resilientbiasing means and said valve member; means for displacing said retainingmeans to permit said resilient biasing means to restore to itsuncompressed configuration and concomitantly actuate saidmotion-transmitting linkage so as to move the valve member from itsopenposition to its closed position. the means for displacing theretaining means comprising a trigger; means biasing said trigger towarda retaining means displacing position; a latch engageable with saidtrigger to retain it in an inoperative position against the restraintexerted by said biasing means; and means for freeing said trigger fromthe restraint exerted by said latch whereby said trigger will movetoward said retaining means to effect a displacement of said retainingmeans and consequent closing of the valve member; and means forthereafter recompressing said resilient biasing means and resetting saidretaining means to the configuration in which it maintains saidbiasingmeans in said compressed configuration, which comprises a fixedlypositioned cam and means for so moving said retaining means relative tosaid cam as to cause said cam to pivotally restore said retaining meansto the position in which it is capable of retaining the resilientbiasing means in the compressed configuration, said retaining meansconcomitantly engaging and restoring said trigger to its inoperativeposition for engagement and retention by said latch. 1

13. The combination of a valve member movable between open and closedpositions and an actuator for said valve member, said actuatorcomprising resilient biasing means; means for retaining said resilientbiasing means in a compressed configuration; a motion-transmittinglinkage operatively connectedbetween said resilient biasing means andsaid valve member; means for displacing said retaining means to permitsaid resilient biasing means to restore to its uncompressedconfiguration and concomitantly actuate said motiontransmitting linkageso as to move the valve member from its open position to its closedposition, the means for displacing the retaining means comprising apivotally mounted trigger; means biasing said trigger toward a retainingmeans displacing position; a latch engageable with said trigger toretain it in an inoperative position against the restraint exerted bysaid biasing means; and means for freeing said trigger from therestraint exerted by said latch whereby said trigger will move towardsaid retaining means to effect a displacement of said retaining meansand consequent closing of the valve member, said trigger having a firstleg provided with means engageable by said latch to retain the triggerin the inoperative position; a second leg engageable with said retainingmeans to displace it from the position in which it retains saidresilient biasing means in the compressed configuration; and a thirdleg, said biasing means being engaged with said third leg; and means forthereafter recompressing said resilient biasing means and resetting saidretaining means to the configuration in which it maintains said biasingmeans in said compressed configuration.

14. The combination of claim 13, wherein said retaining means includes aplurality of relatively movable elements displacement of any one ofwhich from a position in which it is aligned with the remainder of theelements will free said retaining means for displacement from theposition in which said retaining means retains said resilient biasingmeans in the compressed configuration and wherein the displacementeffecting means on said second leg comprises a projection en-

1. An actuator for a valve having a valve member movable between openand closed positions comprising resilient biasing means; a motiontransmitting linkage having a rectilinearly movable input memberoperatively connected to said resilient biasing means and an outputmember adapted to be operatively connected to the valve member;retaining means for retaining said resilient biasing means in acompressed configuration, said last-mentioned means comprising apivotally mounted lever, a plurality of relatively movable elementscarried by said lever, one of said elements being engageable withabutment means on the input member of the motion-transmitting linkage,and means for normally maintaining said relatively movable elementsaligned along an axis parallel to the direction of movement of saidinput member to restrain said member and the resilient biasing meansagainst movement; and means for moving at least one of said movableelements out of alignment with the remainder of said elements to removethe restraint upon the input member and resilient biasing means.
 2. Theactuator of claim 1, wherein said retaining means further includes meansbiasing said lever about its pivot axis toward a position in which therelatively movable elements are aligned along the axis parallel to thedirection of movement of the input member of the motion-transmittinglinkage.
 3. The actuator of claim 1, together with means operable by themovement of one of said relatively movable elements in one directiongenerally at right angles to the direction of movement of the inputmember of the motion-transmitting mechanism out of its aligned positionto displace another of said elements out of its aligned position in theopposite direction.
 4. The combination of a pivotally mounted valvemember movable between open and closed positions and an actuator forsaid valve member, said actuator comprising resilient biasing means;means for retaining said resilient biasing means in a compressedconfiguration; a motion-transmitting linkage operatively connectedbetween said resilient biasing means and said valve member whichincludes a member fixed for rotation with said valve member fordisplacing said retaining means to permit said resilient biasing meansto restore to its uncompressed configuration and concomitantly actuatesaid motion-transmitting linkage so as to move the valve member from itsopen position to its closed position; shock-absorbing means engageableby said fixed member as valve member approaches its closed position tocushion the impact on the components of the valve actuator as the valvemember reaches said closed position; and means for thereafterrecompressing said resilient biasing means and resetting said retainingmeans to the configuration in which it maintains said biasing means insaid compressed configuration.
 5. The combination of claim 4, togetherwith means for indicating the position of the movable valve member. 6.The combination of a valve member movable between open and closedpositions and an actuator for said valve member said actuator comprisingresilient biasing means; means for retaining said resilient biasingmeans in a compressed configuration; a motion-transmitting linkageoperatively connected between said resilient biasing means and saidvalve member which comprises first and second relatively movablemembers, one of said members being engageable with said resilientbiasing means and the means for retaining the resilient biasing means inthe compressed configuration being connected to the second of saidmembers for movement therewith; means for displacing said retainingmeans to permit said resilient biasing means to restore to itsuncompressed configuration and concomitantly actuate saidmotion-transmitting linkage so as to move the valve member from its openposition to its closed position; and means for thereafter recompressingsaid resilient biasing means and resetting said retaining means to theconfiguration in which it maintains said biasing means in saidcompressed configuration, said last-mentioned means including means formoving the second member relative to the first member in a firstdirection; means for restoring said retaining means to the position inwhich it is capable of maintaining the resilient biasing means in acompressed configuration as said second member moves in said firstdirection; and means for thereafter moving said first and second membersin a second direction to recompress said resilient biasing means.
 7. Thecombination of a valve member movable between open and closed positionsand an actuator for said valve member, said actuator comprisingresilient biasing means; means for retaining said resilient biasingmeans in a compressed configuration; a motion-transmitting linkageoperatively connected between said resilient biasing means and saidvalve member, the motion-transmitting linkage comprising first andsecond relatively movable members, one of said members being engageablewith said resilient biasing means, the second relatively movable memberof the motion-transmitting linkage being threaded into a fixed actuatorcomponent, and the means for retaining the resilient biasing means inthe compressed configuration being connected to the second of saidmembers for movement therewith; means for displacing said retainingmeans to permit said resilient biasing means to restore to itsuncompressed configuration and concomitantly actuate saidmotion-transmitting linkage so as to move the valve member from its openposition to its closed position; and means for thereafter recompressingsaid resilient biasing means and resetting said retaining means to theconfiguration in which it maintains said biasing means in saidcompressed configuration, the means for resetting said retaining meansand recompressing said resilient biasing means comprising means formoving the second member relative to the first member in a firstdirection; means for restoring said retaining means to the position inwhich it is capable of maintaining the resilient biasing means in acompressed configuration as said second member moves in said firstdirection; and means for thereafter moving said first and second membersin a second direction to recompress said resilient biasing means, themeans for moving said first member comprising drive means for rotatingsaid member.
 8. The combination of claim 7, wherein said drive meanscoMprises a motor drive connected to said first member.
 9. Thecombination of claim 7, wherein said drive means comprises means forrotating said first member manually.
 10. The combination of a valvemember movable between open and closed positions and an actuator forsaid valve member, said actuator comprising resilient biasing means;means for retaining said resilient biasing means in a compressedconfiguration; a motion-transmitting linkage operatively connectedbetween said resilient biasing means and said valve member whichcomprises a rectilinearly movable input element engageable by saidresilient biasing means, an output member fixed relative to said valvemember for rotation therewith, and an intermediate link pivotally fixedat one end relative to said input member and pivotally fixed at theopposite end to said output member; means for displacing said retainingmeans to permit said resilient biasing means to restore to itsuncompressed configuration and concomitantly actuate saidmotion-transmitting linkage so as to move the valve member from its openposition to its closed position; and means for thereafter recompressingsaid resilient biasing means and resetting said retaining means to theconfiguration in which it maintains said biasing means in saidcompressed configuration.
 11. The combination of a valve member movablebetween open and closed positions and an actuator for said valve member,said actuator comprising resilient biasing means; means for retainingsaid resilient biasing means in a compressed configuration; a motiontransmitting linkage operatively connected between said resilientbiasing means and said valve member which comprises first and secondrelatively movable members, one of said members being engageable withsaid resilient biasing means and the means for retaining the resilientbiasing means in the compressed configuration being connected to thesecond of said members for movement therewith; means for displacing saidretaining means to permit said resilient biasing means to restore to itsuncompressed configuration and concomitantly actuate saidmotion-transmitting linkage so as to move the valve member from its openposition to its closed position; and means for thereafter recompressingsaid resilient biasing means and resetting said retaining means to theconfiguration in which it maintains said biasing means in saidcompressed configuration which comprises means for moving the secondmember relative to the first member in a first direction, means forrestoring said retaining means to the position in which it is capable ofmaintaining the resilient biasing means in a compressed configuration assaid second member moves in said first direction, and means forthereafter moving said first and second members in a second direction torecompress said resilient biasing means, said last-mentioned meansincluding an electric motor, a first switch means for reversing thedirection of rotation of said motor when said first member has moved inthe first direction a distance sufficient to effect reset of saidretaining means and second switch means for deenergizing said motor whensaid first and second members have moved a distance sufficient torecompress the resilient biasing means to its compressed configuration.12. The combination of a valve member movable between open and closedpositions and an actuator for said valve member, said actuatorcomprising resilient biasing means; pivotally mounted means forretaining said resilient biasing means in a compressed configuration; amotion-transmitting linkage operatively connected between said resilientbiasing means and said valve member; means for displacing said retainingmeans to permit said resilient biasing means to restore to itsuncompressed configuration and concomitantly actuate saidmotion-transmitting linkage so as to move the valve member from its openposition to its closed position, the means for displacing the retainingmeans comprising a trigger; means biasing said trigger toward aRetaining means displacing position; a latch engageable with saidtrigger to retain it in an inoperative position against the restraintexerted by said biasing means; and means for freeing said trigger fromthe restraint exerted by said latch whereby said trigger will movetoward said retaining means to effect a displacement of said retainingmeans and consequent closing of the valve member; and means forthereafter recompressing said resilient biasing means and resetting saidretaining means to the configuration in which it maintains said biasingmeans in said compressed configuration, which comprises a fixedlypositioned cam and means for so moving said retaining means relative tosaid cam as to cause said cam to pivotally restore said retaining meansto the position in which it is capable of retaining the resilientbiasing means in the compressed configuration, said retaining meansconcomitantly engaging and restoring said trigger to its inoperativeposition for engagement and retention by said latch.
 13. The combinationof a valve member movable between open and closed positions and anactuator for said valve member, said actuator comprising resilientbiasing means; means for retaining said resilient biasing means in acompressed configuration; a motion-transmitting linkage operativelyconnected between said resilient biasing means and said valve member;means for displacing said retaining means to permit said resilientbiasing means to restore to its uncompressed configuration andconcomitantly actuate said motion-transmitting linkage so as to move thevalve member from its open position to its closed position, the meansfor displacing the retaining means comprising a pivotally mountedtrigger; means biasing said trigger toward a retaining means displacingposition; a latch engageable with said trigger to retain it in aninoperative position against the restraint exerted by said biasingmeans; and means for freeing said trigger from the restraint exerted bysaid latch whereby said trigger will move toward said retaining means toeffect a displacement of said retaining means and consequent closing ofthe valve member, said trigger having a first leg provided with meansengageable by said latch to retain the trigger in the inoperativeposition; a second leg engageable with said retaining means to displaceit from the position in which it retains said resilient biasing means inthe compressed configuration; and a third leg, said biasing means beingengaged with said third leg; and means for thereafter recompressing saidresilient biasing means and resetting said retaining means to theconfiguration in which it maintains said biasing means in saidcompressed configuration.
 14. The combination of claim 13, wherein saidretaining means includes a plurality of relatively movable elementsdisplacement of any one of which from a position in which it is alignedwith the remainder of the elements will free said retaining means fordisplacement from the position in which said retaining means retainssaid resilient biasing means in the compressed configuration and whereinthe displacement effecting means on said second leg comprises aprojection engageable with one of said relatively movable elements todisplace said element upon pivotal movement of said trigger under theinfluence of the biasing means associated therewith.
 15. The combinationof claim 13, wherein the latch engageable means of said first triggerleg comprises a recess in the end thereof opposite that at which thetrigger is pivoted and wherein said latch comprises a pivotally mountedmember adjacent said recessed end of said first trigger leg and a detentcarried by said latch and located opposite said recess, and means forpivoting said latch about its pivot axis to seat said detent in therecess in the trigger leg.
 16. The combination of a valve member movablebetween open and closed positions and an actuator for said valve membersaid actuator comprising resilient biasing means; means for retainingsaId resilient biasing means in a compressed configuration; amotion-transmitting linkage operatively connected between said resilientbiasing means and said valve member; means for displacing said retainingmeans to permit said resilient biasing means to restore to itsuncompressed configuration and concomitantly actuate saidmotion-transmitting linkage so as to move the valve member from its openposition to its closed position, the means for displacing the retainingmeans comprising a trigger; means biasing said trigger toward aretaining means displacing position; a latch engageable with saidtrigger to retain it in an inoperative position against the restraintexerted by said biasing means; and means for freeing said trigger fromthe restraint exerted by said latch, whereby said trigger will movetoward said retaining means to effect a displacement of said retainingmeans and consequent closing of the valve member, said last-mentionedmeans comprising a pivotally mounted double-armed crank having one armengageable with said trigger to free it from the restraint exerted bysaid latch and means so operatively connecting said motion-transmittinglinkage to the other arm of said crank that movement of the valve membertoward its closed position exceeding a minimum magnitude will throughsaid linkage move said one arm of said crank a distance sufficient tofree said trigger from the restraint exerted by said latch; and meansfor thereafter recompressing said resilient biasing means and resettingsaid retaining means to the configuration in which it maintains saidbiasing means in said compressed configuration.
 17. The combination of avalve member movable between open and closed positions and a actuatorfor said valve member, said actuator comprising resilient biasing means;means for retaining said resilient biasing means in a compressedconfiguration; a motion-transmitting mechanism operatively connectedbetween said resilient biasing means and said valve member whichcomprises an input member engageable by said resilient biasing means, anoutput member operably connected to said valve member, an intermediatelink disposed between said input and output members, first meansoperably connecting said intermediate link to said output member, andsecond means so connecting said intermediate link to said input memberas to permit limited relative movement therebetween, wherebyoverpressure-generated movement of said valve member will effectmovement of said intermediate link irrespective of the absence ofmovement of said input member; means for displacing said retaining meansto permit said resilient biasing means to restore to its uncompressedconfiguration and concomitantly actuate said motion-transmitting linkageso as to move the valve member from its open position to its closedposition, the means for displacing the retaining means comprising atrigger; means biasing said trigger toward a retaining means displacingposition; a latch engageable with said trigger to retain it in aninoperative position against the restraint exerted by said biasingmeans; and means for freeing said trigger from the restraint exerted bysaid latch whereby said trigger will move toward said retaining means toeffect a displacement of said retaining means and consequent closing ofthe valve member, the means for freeing the trigger from the restraintexerted by the latch comprising a pivotally mounted double-armed crankhaving one arm engageable with said trigger to free it from therestraint exerted by said latch and means so operatively connecting saidmotion-transmitting linkage to the other arm of said crank that movementof the valve member toward its closed position exceeding a minimummagnitude will through said linkage move said one arm of said crank adistance sufficient to free said trigger from the restraint exerted bysaid latch, the means operatively connecting the pivotally mounted crankto the motion-transmitting mechanism comprising means pivotallyconnecting said other arm of said crAnk to said intermediate link; andmeans for thereafter recompressing said resilient biasing means andresetting said retaining means to the configuration in which itmaintains said biasing means in said compressed configuration.
 18. Thecombination of claim 17, together with means operatively disposedbetween said input member and said intermediate link and biasing saidlink in a direction in which said link tends to maintain said valvemember in a fully open position and to maintain said one arm of saiddouble-armed crank out of engagement with said trigger.
 19. An actuatorfor a valve having a valve member movable between open and closedpositions comprising resilient biasing means; a motion-transmittinglinkage having a rectilinearly movable input member operativelyconnected to said resilient biasing means and an output member adaptedto be operatively connected to the valve member; retaining means forretaining said resilient biasing means in a compressed configuration,said last-mentioned means comprising a pivotally mounted lever, aplurality of relatively movable elements carried by said lever, saidrelatively movable elements being rollers oriented with theirlongitudinal axes at right angles relative to the direction of movementof the input member of the motion-transmitting mechanism with the endportions of said rollers disposed in cooperating grooves in said leverso configured as to permit relative movement between the rollers and thelever and one of said elements being engageable with abutment means onthe input member of the motion-transmitting linkage, and means fornormally maintaining said relatively movable elements aligned along anaxis parallel to the direction of movement of said input member torestrain said member and the resilient biasing means against movement;and means for moving at least one of said movable elements out ofalignment with the remainder of said elements to remove the restraintupon the input member and resilient biasing means.
 20. The actuator ofclaim 19, wherein the abutment means on the input member of the motiontransmitting mechanism comprises a shoulder on said member and acylindrical member fixed to said input member in juxtaposition to saidshoulder, the longitudinal axis of said cylindrical member lying in thesame plane as the axes of the relatively movable rollers with theretaining means in the position in which it retains the resilientbiasing means in the compressed configuration.
 21. An actuator for avalve having a valve member movable between open and closed positionscomprising resilient biasing means; a motion-transmitting linkage havinga rectilinearly movable input member operatively connected to saidresilient biasing means and an output member adapted to be operativelyconnected to the valve member; retaining means for retaining saidresilient biasing means in a compressed configuration, saidlast-mentioned means comprising a pivotally mounted lever, a pluralityof relatively movable elements carried by said lever, one of saidelements being engageable with abutment means on the input member of themotion-transmitting linkage, and means for normally maintaining saidrelatively movable elements aligned along an axis parallel to thedirection of movement of said input member to restrain said member andthe resilient biasing means against movement; means for moving at leastone of said movable elements out of alignment with the remainder of saidelements to remove the restraint upon the input member and resilientbiasing means; and means operable by the movement of one of saidrelatively movable elements in one direction generally at right anglesto the direction of movement of the input member of themotion-transmitting mechanism out of its aligned position to displaceanother of said elements out of its aligned position in the oppositedirection, said last-mentioned means comprising a member mounted forrocking movement along an axis parallel to the direction of movement ofthe input memBer of the motion-transmitting mechanism, first and secondmembers disposed between said rockable member and different ones of saidrelatively movable elements, said first and second members being onopposite sides of the axis about which said rockable member rocks, andmeans biasing said rockable member into engagement with said first andsecond members and said first and second members into engagement withthe associated relatively movable elements, whereby movement of one ofthe elements associated with said first and second members in said onedirection out of its aligned position will effect movement of the otherof the relatively movable elements associated with said first and secondmembers out of its aligned position in said opposite direction.